... w/o ill effects? i know ford put out a TSB on the use of 5-20 in older Fords, but i'm wondering if anyone switched and noticed anyhting different good or bad? i have a 98' w/ a 4.6 and was thinking of going to the 5-20 for the mileage improvement.

so who's tried it?

 

I didn't go from 5W-30 to 5W-20, I've always run the 5W-20 Motorcraft Synthetic Blend with Motorcraft FL-820S filters.

I change it every 3,000 miles and have nothing to report, other than no problems so far.

Not to be a weirdo, but I have yet to meet ANYONE who has had a properly maintained vehicle that has had an oil-related failure.

Even those who run Quaker State (AHHH!!!) are probably safe with a strict regimen of maintenance...

I'm not saying that the oil is un-important, but it probably doesn't warrant as much attention as it gets here.

Witness all the different brands, change intervals, filters, etc. and everyone is happy with what they run...

Just my $.02

 

The only thing I noticed was that I had piece of mind when I made the switch to 5w-30, then again to 10w-30.
Now, I feel much better...not to mention all the weird noises are gone with the thicker oil.

 

Here is the thread back in July 2000 on that topic.

https://www.f150online.com/forums/sh...threadid=66593

The point made is that the fuel savings from going to the 5w-20 is not measurable or noticable by the average truck owner, but will impact Ford's CAFE numbers reported to the government.

Now I understand why some here say that 5w-30 is a better choice, and 0w-30 synthetic is often used. I'm at 30,000 which is decision point. I was thinking either Mobile 1 0w-20, Royal Purple 5w-20, or Amsoil 0w030.

After reading the article, I have decided to go with the Amsoil 0w-30. I'm also going to plan on using Mobile 1 0w-30 in my John Deere riding lawn mower, which calls for 5w-30 dino.

The 5w-20 doesn't seem to be a big hit. I talked to two Royal Purple dealers in the area who did not know that RP made a 5w-20.

 

My truck specifies 5W30. But with Mobil 1 prices going up. Cheapest place in town here is $28.56 for 6 quarts at Walmart. I'm using Motorcraft 5W20 and oil filter. Believe it or not, I notice in cold morning startups, it's not as noisy. I can get six quarts of Motorcraft for $12.00. No difference in mileage but I still change oil every 2500-3000 miles.

 

I am using 0w30 mobil1 without any problems..